1. Field of Invention
The present invention relates to a complementary thin film transistor circuit (hereinafter, a CMOS circuit) including thin film transistors (TFTs). More particularly, the present invention relates to a complementary thin film transistor circuit including thin film transistors using a substantially monocrystalline semiconductor film made by performing laser irradiation on a semiconductor film, an electro-optical device, and an electronic apparatus using the same.
2. Description of Related Art
As a method to fabricate a thin film transistor on a general purpose glass substrate at a low temperature, a related art method has been disclosed. A hole is formed in an insulating film on a substrate, an amorphous silicon film is formed on this insulating film and in the hole. Thereafter laser is irradiated on the amorphous silicon film, while maintaining amorphous silicon in a bottom portion of the hole in an unmelted state and the other portions of the amorphous silicon film in a melted state, in order to stimulate crystal growth using the amorphous silicon film that is maintained in non-melted state as a crystal nucleus. Thereby a region is provided centered on the hole in a surface of the amorphous silicon film as a substantially monocrystalline silicon film, See “Single Crystal Thin Film Transistors” (IBM TECHNICAL DISCLOSURE BULLETIN August 1993 pp 257-258) and “Advanced Excimer-Laser Crystallization Techniques of Si Thin-Film For Location Control of Large Grain on Glass” (R. Ishihara et al., proc. SPIE 2001, vol. 4295, p 14-23) described below.
Because this substantially monocrystalline semiconductor film has no crystal grain boundary or less crystal grain boundaries, a barrier, when carriers such as electrons or holes flow, is significantly reduced as compared to a polycrystalline semiconductor film.
By constructing a semiconductor device using this substantially monocrystalline semiconductor film in the semiconductor thin film, an off-current suppressing effect or mobility thereof is good, thereby being capable of easily realizing a thin film transistor that is compatible with high-speed operation.